The subject matter herein relates generally to caged electrical connector assemblies for high speed optical and electrical communication systems.
It is known to provide a metal cage with a plurality of ports, whereby transceiver modules are pluggable therein. Several pluggable module designs and standards have been introduced in which a pluggable module plugs into a receptacle which is electronically connected to a host circuit board. For example, a well-known type of transceiver developed by an industry consortium is known as a gigabit interface converter (GBIC) or serial optical converter (SOC) and provides an interface between a computer and a data communication network such as Ethernet or a fiber network. These standards offer a generally robust design which has been well received in industry.
It is desirable to increase the operating frequency of the network connections. Electrical connector systems that are used at increased operating speeds present a number of design problems, particularly in applications in which data transmission rates are high, for example, in the range above 10 Gbps (Gigabits/second). One concern with such systems is reducing electromagnetic interference (EMI) emissions. Another concern is reducing operating temperatures of the transceivers.
In conventional designs, thermal cooling is achieved by using a heat sink and/or airflow over the outside of the shielding metal cage surrounding the receptacles. However, the thermal cooling provided by conventional designs is proving to be inadequate, particularly for pluggable modules in interior or lower ports, which tend to have less cage wall surface area exposed to airflow for cooling. Some pluggable module designs have incorporated heat dissipating fins into the pluggable modules to increase the surface area exposed to airflow along the shells of the pluggable modules, such as with the fins extending from the tops of the pluggable modules. Cage designs have been designed to accommodate the pluggable modules with the heat dissipating fins, such as by eliminating the central channel between stacked pluggable modules to accommodate the taller pluggable modules. However, the channels were previously used for routing light pipes to provide connector status indicators at the front face of the systems. By eliminating the channels, the space for routing light pipes has also been eliminated.
A need remains for an electrical connector assembly having improved thermal cooling and providing connector status indication at the front face of the cage.